1. Field of the Invention
This invention relates in general to water faucets and more particularly to a washerless faucet of the type employing ceramic discs for flow control purposes in combination with an adjustable stem tightening structure which prevents unintentional rotational opening of the valve when mounted in a horizontal attitude and having a control lever mounted thereon.
2. Description of the Prior Art
For many years, water faucets used valves of the type having threaded stems that were axially moved in internally threaded bores provided in the valve body. A washer is demountably carried on the innermost end of the stem and is axially movable with the stem into seated and out of seated engagement with a valve seat provided within the valve body. It is well known that seat damage, washer wear and/or damage, corrosion, and the like, are weaknesses of this type of valve which make them prone to leakage and other operational difficulties which require relatively frequent maintenance and repair.
For these well known reasons, a relatively new general type of faucet valve has been developed and this faucet valve, which is becoming increasingly used, is known generally in the art as a washerless faucet valve.
One particular type of washerless faucet valve utilizes a matched pair of contiguously disposed ceramic discs one of which is held against rotation in a valve housing with the other being coupled for rotation with a rotatably movable valve stem carried in a smooth bore formed in the valve housing. Rotation of the valve stem through approximately 90 degrees of rotation will move matching apertures provided in the two discs into alignment for flow control purposes and out of alignment for shutoff purposes. The valve stem carries a spaced pair of O-ring type seals which engage the smooth bore of the valve body and prevent leakage around the stem.
This particular valve is an excellently operating structure which is virtually maintenance free. However, it cannot be mounted in a horizontal attitude with a control lever mounted on the extending end of the valve stem. The weight of the laterally extending handle portion of the control lever applies rotational forces on the valve stem and the friction of the O-ring type seals is insufficient to keep the stem from rotating to the open position. This problem is particularly bad whenever vibrations occur in the water pipes or the wall structure in which the faucet is mounted.
For this reason, this otherwise excellent faucet valve is limited to vertical installations, or to horizontal installations which employ a round control knob rather than a control lever.
Therefore, a need exists for an adjustable valve stem tightening structure for use in combination with the above described faucet valve which overcomes that shortcoming of the faucet valve.